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(No Model.)

I D. W. BROWN.

- TENSION DEVICE EOE SEWING MACHINES. No. 254,603. Patented Mar.-7,1882

WITNESSES. eNvEN TOR.

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wA Perma mmm-mmm wnsmngm Dfl K UNITED STATES PATENT OEI-TICE.

DANIEL W. BROWN, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO JOHN B.ANTHONY, OF SAME PLACE.

TENSION DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 254,603, dated March'7, 1882,

l Application filed May 2, 1881. (No model.)

To all whom it may concern Be it known that I, DANIEL W. BROWN, of thecity and county of Providence and State of Rhode Island,have invented anew and useful Improvement in Sewing-Machines; and I do hereby declarethat the following specification, taken in connection with theaccompanyingdrawings, forming a part ofthe same, is a full, clear, andexact description thereof.

My improvement relates to a tension device of novel constructionattached to the needlebar, whereby the needle-thread above the eye ofthe needle is lifted bodily with the needle, thus assuring the formationof a proper loop :for the passage of the shuttle,snbstantially asheretofore,with tension devices variously constructed,but operating uponthe same general principle.

My invention consists in a needle-bar tenzo sion device embodied withinthe head of the needle-clamp bolt, which is vertically recessed for thereception of thread extending downward to the needle, and is laterallyrecessed for the reception of a lateral tension pin or bar, z 5 whichlies across' the vertical recess, so that the thread in line with theneedle-eye and the usual thread-eyes above the needle may also pass tothe rearof and be frictionally engaged by said bar or pin and by aneighboring surface ofthe bolt-head. With this construction a desirableintermediate-tension device is obtained at low cost, and no portionthereof unduly projects beyond the needle-bar, and it is therefore notliable to strike or cha-fe the hands 3 5 of the operator.

Referring to the drawings, Figures 1, 2, and 3 represent, inperspective, vertical section, and side view,respectively,a portion of aneedle-bar, A, a needle, B, and a clamp-bolt, O, 4o the head of which isconstructed to produce the desired tension or friction upon the thread.As shown in these views, the bolt-head is provided with a verticalgroove, c, a horizontal groove, c', and a pin,d, which extends throughthe latter groove. The thread passes behind the pin d and in engagementwith its rear sur face, then down through the groove cto the needle-eye,as shown in Fig.2. It will be seen that the needle-thread isreadilypassed behind the thread-pin from its outer end, and that 5o when inthat position, as the needle rises, the usual tension on the threadabove the clampbolt causes the thread to be frictionally engaged notonly by the rear surface of the pin y d, but also by the bolt-head atthe edge presented at the upper end of the vertical recess c, thusmaking a short turn or angle in the line of the thread, which enablesthe thread to be lifted bodily with the needle as it rises. The size ofthe clamp-bolt head need be but 6o little, if any, larger thanheretofore to admit of the necessary recessing thereof; and it will beseen that the friction-pin is well housed within the head, and thatthere is no undue projection from the needle-bar to provide for theattainment of the ends sought. Heretofore intermediate or needle-bartension devices for the same purpose have sometimes been separatelyconstructed and applied to the needle-bar, and sometimestheclamping-bolthasbeen provided 7o with a spirally-grooved stud or pinprojecting outward therefrom, and around which the thread is wrapped,and in other cases a projecting clamping tension device has beenseparately constructed and applied to the head of 'the needle-clampingscrew or bolt.

In Fig. 3 I have shown the usual brd-plate, E e, the fabric F,`and theneedle at its lowest position, it being understood that the friction ofthe thread with the pin and the bolt-head will be sufcient tc cause thethread to be lifted bodily bythe needle,instead of permitting the fabricto hold the thread down when the needle rises.

What I claim as my invention, and desire to secure by Letters Patent, is

'lho intermediate or needle-bar tension device, consisting ot' theneedle-clamp bolt, having a head grooved or recessed vertically andlaterally,in combination withalateral threadpin occupying said lateralrecess in said head, substantially as described.

DANIEL W. BROWN. Witnesses:

W. H. THURs'roN, I. KNIGHT.

